1. Field of the Invention
The present invention relates to an ink jet recording head, an ink jet recording cartridge having an ink jet recording head and a recording apparatus.
The present invention is applicable to a printer, a copying machine, a facsimile having a communication system, an apparatus having a printer unit such as a word processor, and further an industrial recording apparatus combined with various processors in a complex constitution for recording into a record medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. xe2x80x9cRecordxe2x80x9d in this invention means not only giving an image having a meaning of characters or graphics to the record medium, but giving an image having no meaning such as a pattern.
2. Related Background Art
In various types of electronic equipment such as a computer, a word processor, a facsimile device, and a copying machine, an ink jet recording head which enables high-speed recording is widely used as a means for recording into record mediums without generating noises like ones generated by a dot impact printer.
Referring to FIG. 23, there is shown a schematic perspective view outlining a main portion of a conventional ink jet recording head. Referring to FIG. 24, there is shown its expanded sectional view.
As shown in FIGS. 23 and 24, an element base 112 having energy generating elements 102 (See FIG. 24) for generating energy used for discharging ink is joined to a grooved top plate 113 having grooves forming ink flow channels 105, a wall portion 106 to be an ink flow channel wall, and a hollow 107xe2x80x2 to be a common liquid chamber 107 for supplying ink to the ink flow channels 105. The grooved top plate 113 includes an orifice plate 104 having a plurality of orifices 101 for communication with the ink flow channels 105, with being integrally formed. The element base 112 is fixed to a base plate 111, and further the element base 112 is mechanically contact-bonded to the grooved top plate 113 with a spring force of a pushing member 114.
In recent years, a high-quality and high-density recording is required for this type of the ink jet recording head and it has brought with it a requirement of the orifices 101 having fine and accurate shapes. Accordingly, the orifices 101 are generally formed by laser processing suitable for fine processing. On the characteristics of the orifices, it is desirable that the orifices 101 have shapes converging in a direction from the side of the ink flow channels 105 to the outside, and therefore the orifices are irradiated for the processing with laser light in a direction from the side of the ink flow channels 105 to the orifice plate 104.
As shown in FIG. 24, if the orifice plate 104 is perpendicularly irradiated with laser light (indicated by a long and two short dashes line 116), the laser light is inevitably applied to a wall portion 113a of the grooved top plate 113, by which the applied portion is scraped. This makes a hole from which ink leaks into the ink flow channels 105, by which the ink cannot be discharged. Accordingly, laser light is applied diagonally (indicated by a long and two short dashes line 115) so as to avoid the wall portion 113a when making the orifices 101 diagonally to the orifice plate (Angle of inclination: Approx. 70 to 83 deg). If ink is discharged diagonally to a record medium 103 in recording, however, the discharge direction becomes unstable or dot shapes formed on the record medium tend to be uniformless and enlarged, in other words, the recording quality is deteriorated. Particularly in color printing, a dotted point depends upon each color, by which color-shading or satellite significantly deteriorates an image in some cases in multipath printing at cockling of a record medium or in reciprocating printing.
Therefore, there is suggested a constitution for improving a recording quality by attaching an ink jet recording head to a recording apparatus in an inclined position so that ink is discharged perpendicularly to the record medium in a Japanese Patent Laid-Open Application No. 4-211954.
While the invention in the Japanese Patent Laid-Open Application No. 4-211954 was a practically effective, new problems were found in such a case that a large cockling (a wrinkle or an undulation) may be caused by an absorption of ink on a record medium, particularly a recording sheet or that a mist may adhere to the orifice plate and accumulated.
If the entire ink jet recording head is inclined, the orifice plate is not put in a parallel state with the record medium, but necessarily put in a slightly inclined (approx. 7 to 20 deg) state. Therefore, a large cockling of the record medium causes the record medium to be partially put in contact with the orifice plate since they are too close to each other, by which the recording quality may be partially degraded.
The mist adhering to and accumulated on the orifice plate is generally retained on the orifice plate under an adhering state without affecting the record medium. If the orifice plate is inclined as described above, however, the mist easily moves to one direction being affected by an inertia force caused by a reciprocating motion of the ink jet recording head, and therefore there is a possibility of the mist separating from the orifice plate to adhere to the record medium or the recording apparatus or other components. Particularly the possibility is significant if the adhering mist is accumulated to a large amount or if the ink jet recording head reciprocates at a high speed in high-speed recording.
Therefore it is an object of the present invention to provide an ink jet recording head and an ink jet recording cartridge which enable high-quality recording without being so much affected by cockling of a record medium nor high-speed motion and further to provide a recording apparatus having these ink jet recording head and the ink jet recording cartridge.
It is another object of the present invention to provide an ink jet recording head comprising an element base having a plurality of energy generating elements for generating energy used for discharging ink, a grooved top plate having a plurality of grooves corresponding to the plurality of energy generating elements, being joined to the element base, and having a plurality of ink flow channels formed by the plurality of grooves on a joint area side to the element base, an orifice plate having a plurality of orifices having communication with the plurality of ink flow channels respectively and being mounted on the grooved top plate integrally, and a chip tank having supply passages for supplying ink to the plurality of ink flow channels and having a shroud portion for shrouding the orifice plate, wherein a surface in the side of the plurality of orifices of the orifice plate is substantially parallel with the shroud portion of the chip tank and is inclined relative to the element base.
It is still another object of the present invention to provide an ink jet recording head comprising an element base having a plurality of energy generating elements for generating energy used for discharging ink, a grooved top plate having a plurality of grooves corresponding to the plurality of energy generating elements, being joined to the element base, and having a plurality of ink flow channels formed by the plurality of grooves on a joint area side to the element base, and an orifice plate having a plurality of orifices having communication with the plurality of ink flow channels respectively, having a recess surface formed on the area in which the plurality of orifices are arranged, and being mounted on the grooved top plate integrally, wherein an area closest to the plurality of orifices among surfaces in the side of the plurality of orifices of the orifice plate is substantially parallel with peripheral areas of the recess surface of the orifice plate and is inclined to the element base.
It is a further object of the present invention to provide an ink jet recording cartridge comprising an ink jet recording head unit including an element base having a plurality of energy generating elements for generating energy used for discharging ink, a base plate for fixing the element base and, a grooved top plate having a plurality of grooves corresponding to the plurality of energy generating elements respectively, being joined to the element base, and having a plurality of ink flow channels formed by the plurality of grooves on a joint area side to the element base, and a head unit retaining member including an engaging groove portion where the ink jet recording head unit can be retained with the base plate inserted and a guide portion for guiding the ink jet recording head unit to the engaging groove portion by sliding the base plate.
It is a still further object of the present invention to provide an ink jet recording cartridge comprising an ink jet recording head unit for discharging ink, a head unit retaining member for retaining the ink jet recording head unit, and an ink tank retaining member for retaining an ink tank for containing ink, wherein the ink jet recording head unit is provided with an inlet to which ink is supplied, the ink tank retaining member is provided with an outlet tube for flowing out the ink connected to the ink tank, and the inlet is connected to the outlet tube so as to enable the ink to flow, and wherein the head unit retaining member is connected to the ink tank retaining member.
It is another object of the present invention to provide a recording apparatus comprising an ink jet recording head or an ink jet recording cartridge having the above constitution and a record medium conveying means for conveying a record medium arranged substantially perpendicularly to a discharge direction of ink discharged from the ink jet recording head or the ink jet recording cartridge.
In the present invention, the orifice plate is inclined to the element base, by which it can be arranged in parallel with the record medium surface and ink can be discharged perpendicularly to the record medium. Therefore, high-quality recording is achieved without being so much affected by cockling of a record medium or a high-speed motion.
Furthermore in a constitution in which a guide portion is arranged continuously from a head unit positioning reference surface of an engaging groove portion of a head unit retaining member, a head unit can be easily attached with a high positioning precision by sliding a base plate to an engaging groove portion along a guide portion continuously arranged from a head unit positioning reference surface when the head unit is attached to a head unit retaining member.
Furthermore, in a constitution in which an ink tank is attached to a head unit retaining member through an ink tank retaining member, a shock or vibrations generated at an attachment or detachment of the ink tanks can be relieved by the ink tank retaining member or a head unit fixing member, by which the shock or vibrations can be reduced before they are transmitted to the head unit.